1 /* GNU/Linux/MIPS specific low level interface, for the remote server for GDB.
2 Copyright (C) 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2005, 2006, 2007,
3 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
4
5 This file is part of GDB.
6
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
11
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
19
20 #include "server.h"
21 #include "linux-low.h"
22
23 #include <sys/ptrace.h>
24 #include <endian.h>
25
26 #include "gdb_proc_service.h"
27
28 /* Defined in auto-generated file mips-linux.c. */
29 void init_registers_mips_linux (void);
30 /* Defined in auto-generated file mips64-linux.c. */
31 void init_registers_mips64_linux (void);
32
33 #ifndef PTRACE_GET_THREAD_AREA
34 #define PTRACE_GET_THREAD_AREA 25
35 #endif
36
37 #ifdef HAVE_SYS_REG_H
38 #include <sys/reg.h>
39 #endif
40
41 #define mips_num_regs 73
42
43 #include <asm/ptrace.h>
44
45 union mips_register
46 {
47 unsigned char buf[8];
48
49 /* Deliberately signed, for proper sign extension. */
50 int reg32;
51 long long reg64;
52 };
53
54 /* Return the ptrace ``address'' of register REGNO. */
55
56 static int mips_regmap[] = {
57 -1, 1, 2, 3, 4, 5, 6, 7,
58 8, 9, 10, 11, 12, 13, 14, 15,
59 16, 17, 18, 19, 20, 21, 22, 23,
60 24, 25, 26, 27, 28, 29, 30, 31,
61
62 -1, MMLO, MMHI, BADVADDR, CAUSE, PC,
63
64 FPR_BASE, FPR_BASE + 1, FPR_BASE + 2, FPR_BASE + 3,
65 FPR_BASE + 4, FPR_BASE + 5, FPR_BASE + 6, FPR_BASE + 7,
66 FPR_BASE + 8, FPR_BASE + 8, FPR_BASE + 10, FPR_BASE + 11,
67 FPR_BASE + 12, FPR_BASE + 13, FPR_BASE + 14, FPR_BASE + 15,
68 FPR_BASE + 16, FPR_BASE + 17, FPR_BASE + 18, FPR_BASE + 19,
69 FPR_BASE + 20, FPR_BASE + 21, FPR_BASE + 22, FPR_BASE + 23,
70 FPR_BASE + 24, FPR_BASE + 25, FPR_BASE + 26, FPR_BASE + 27,
71 FPR_BASE + 28, FPR_BASE + 29, FPR_BASE + 30, FPR_BASE + 31,
72 FPC_CSR, FPC_EIR,
73
74 0
75 };
76
77 /* From mips-linux-nat.c. */
78
79 /* Pseudo registers can not be read. ptrace does not provide a way to
80 read (or set) PS_REGNUM, and there's no point in reading or setting
81 ZERO_REGNUM. We also can not set BADVADDR, CAUSE, or FCRIR via
82 ptrace(). */
83
84 static int
mips_cannot_fetch_register(int regno)85 mips_cannot_fetch_register (int regno)
86 {
87 if (mips_regmap[regno] == -1)
88 return 1;
89
90 if (find_regno ("r0") == regno)
91 return 1;
92
93 return 0;
94 }
95
96 static int
mips_cannot_store_register(int regno)97 mips_cannot_store_register (int regno)
98 {
99 if (mips_regmap[regno] == -1)
100 return 1;
101
102 if (find_regno ("r0") == regno)
103 return 1;
104
105 if (find_regno ("cause") == regno)
106 return 1;
107
108 if (find_regno ("badvaddr") == regno)
109 return 1;
110
111 if (find_regno ("fir") == regno)
112 return 1;
113
114 return 0;
115 }
116
117 static CORE_ADDR
mips_get_pc(struct regcache * regcache)118 mips_get_pc (struct regcache *regcache)
119 {
120 union mips_register pc;
121 collect_register_by_name (regcache, "pc", pc.buf);
122 return register_size (0) == 4 ? pc.reg32 : pc.reg64;
123 }
124
125 static void
mips_set_pc(struct regcache * regcache,CORE_ADDR pc)126 mips_set_pc (struct regcache *regcache, CORE_ADDR pc)
127 {
128 union mips_register newpc;
129 if (register_size (0) == 4)
130 newpc.reg32 = pc;
131 else
132 newpc.reg64 = pc;
133
134 supply_register_by_name (regcache, "pc", newpc.buf);
135 }
136
137 /* Correct in either endianness. */
138 static const unsigned int mips_breakpoint = 0x0005000d;
139 #define mips_breakpoint_len 4
140
141 /* We only place breakpoints in empty marker functions, and thread locking
142 is outside of the function. So rather than importing software single-step,
143 we can just run until exit. */
144 static CORE_ADDR
mips_reinsert_addr(void)145 mips_reinsert_addr (void)
146 {
147 struct regcache *regcache = get_thread_regcache (current_inferior, 1);
148 union mips_register ra;
149 collect_register_by_name (regcache, "r31", ra.buf);
150 return register_size (0) == 4 ? ra.reg32 : ra.reg64;
151 }
152
153 static int
mips_breakpoint_at(CORE_ADDR where)154 mips_breakpoint_at (CORE_ADDR where)
155 {
156 unsigned int insn;
157
158 (*the_target->read_memory) (where, (unsigned char *) &insn, 4);
159 if (insn == mips_breakpoint)
160 return 1;
161
162 /* If necessary, recognize more trap instructions here. GDB only uses the
163 one. */
164 return 0;
165 }
166
167 /* Fetch the thread-local storage pointer for libthread_db. */
168
169 ps_err_e
ps_get_thread_area(const struct ps_prochandle * ph,lwpid_t lwpid,int idx,void ** base)170 ps_get_thread_area (const struct ps_prochandle *ph,
171 lwpid_t lwpid, int idx, void **base)
172 {
173 if (ptrace (PTRACE_GET_THREAD_AREA, lwpid, NULL, base) != 0)
174 return PS_ERR;
175
176 /* IDX is the bias from the thread pointer to the beginning of the
177 thread descriptor. It has to be subtracted due to implementation
178 quirks in libthread_db. */
179 *base = (void *) ((char *)*base - idx);
180
181 return PS_OK;
182 }
183
184 #ifdef HAVE_PTRACE_GETREGS
185
186 static void
mips_collect_register(struct regcache * regcache,int use_64bit,int regno,union mips_register * reg)187 mips_collect_register (struct regcache *regcache,
188 int use_64bit, int regno, union mips_register *reg)
189 {
190 union mips_register tmp_reg;
191
192 if (use_64bit)
193 {
194 collect_register (regcache, regno, &tmp_reg.reg64);
195 *reg = tmp_reg;
196 }
197 else
198 {
199 collect_register (regcache, regno, &tmp_reg.reg32);
200 reg->reg64 = tmp_reg.reg32;
201 }
202 }
203
204 static void
mips_supply_register(struct regcache * regcache,int use_64bit,int regno,const union mips_register * reg)205 mips_supply_register (struct regcache *regcache,
206 int use_64bit, int regno, const union mips_register *reg)
207 {
208 int offset = 0;
209
210 /* For big-endian 32-bit targets, ignore the high four bytes of each
211 eight-byte slot. */
212 if (__BYTE_ORDER == __BIG_ENDIAN && !use_64bit)
213 offset = 4;
214
215 supply_register (regcache, regno, reg->buf + offset);
216 }
217
218 static void
mips_collect_register_32bit(struct regcache * regcache,int use_64bit,int regno,unsigned char * buf)219 mips_collect_register_32bit (struct regcache *regcache,
220 int use_64bit, int regno, unsigned char *buf)
221 {
222 union mips_register tmp_reg;
223 int reg32;
224
225 mips_collect_register (regcache, use_64bit, regno, &tmp_reg);
226 reg32 = tmp_reg.reg64;
227 memcpy (buf, ®32, 4);
228 }
229
230 static void
mips_supply_register_32bit(struct regcache * regcache,int use_64bit,int regno,const unsigned char * buf)231 mips_supply_register_32bit (struct regcache *regcache,
232 int use_64bit, int regno, const unsigned char *buf)
233 {
234 union mips_register tmp_reg;
235 int reg32;
236
237 memcpy (®32, buf, 4);
238 tmp_reg.reg64 = reg32;
239 mips_supply_register (regcache, use_64bit, regno, &tmp_reg);
240 }
241
242 static void
mips_fill_gregset(struct regcache * regcache,void * buf)243 mips_fill_gregset (struct regcache *regcache, void *buf)
244 {
245 union mips_register *regset = buf;
246 int i, use_64bit;
247
248 use_64bit = (register_size (0) == 8);
249
250 for (i = 1; i < 32; i++)
251 mips_collect_register (regcache, use_64bit, i, regset + i);
252
253 mips_collect_register (regcache, use_64bit,
254 find_regno ("lo"), regset + 32);
255 mips_collect_register (regcache, use_64bit,
256 find_regno ("hi"), regset + 33);
257 mips_collect_register (regcache, use_64bit,
258 find_regno ("pc"), regset + 34);
259 mips_collect_register (regcache, use_64bit,
260 find_regno ("badvaddr"), regset + 35);
261 mips_collect_register (regcache, use_64bit,
262 find_regno ("status"), regset + 36);
263 mips_collect_register (regcache, use_64bit,
264 find_regno ("cause"), regset + 37);
265
266 mips_collect_register (regcache, use_64bit,
267 find_regno ("restart"), regset + 0);
268 }
269
270 static void
mips_store_gregset(struct regcache * regcache,const void * buf)271 mips_store_gregset (struct regcache *regcache, const void *buf)
272 {
273 const union mips_register *regset = buf;
274 int i, use_64bit;
275
276 use_64bit = (register_size (0) == 8);
277
278 for (i = 0; i < 32; i++)
279 mips_supply_register (regcache, use_64bit, i, regset + i);
280
281 mips_supply_register (regcache, use_64bit, find_regno ("lo"), regset + 32);
282 mips_supply_register (regcache, use_64bit, find_regno ("hi"), regset + 33);
283 mips_supply_register (regcache, use_64bit, find_regno ("pc"), regset + 34);
284 mips_supply_register (regcache, use_64bit,
285 find_regno ("badvaddr"), regset + 35);
286 mips_supply_register (regcache, use_64bit,
287 find_regno ("status"), regset + 36);
288 mips_supply_register (regcache, use_64bit,
289 find_regno ("cause"), regset + 37);
290
291 mips_supply_register (regcache, use_64bit,
292 find_regno ("restart"), regset + 0);
293 }
294
295 static void
mips_fill_fpregset(struct regcache * regcache,void * buf)296 mips_fill_fpregset (struct regcache *regcache, void *buf)
297 {
298 union mips_register *regset = buf;
299 int i, use_64bit, first_fp, big_endian;
300
301 use_64bit = (register_size (0) == 8);
302 first_fp = find_regno ("f0");
303 big_endian = (__BYTE_ORDER == __BIG_ENDIAN);
304
305 /* See GDB for a discussion of this peculiar layout. */
306 for (i = 0; i < 32; i++)
307 if (use_64bit)
308 collect_register (regcache, first_fp + i, regset[i].buf);
309 else
310 collect_register (regcache, first_fp + i,
311 regset[i & ~1].buf + 4 * (big_endian != (i & 1)));
312
313 mips_collect_register_32bit (regcache, use_64bit,
314 find_regno ("fcsr"), regset[32].buf);
315 mips_collect_register_32bit (regcache, use_64bit, find_regno ("fir"),
316 regset[32].buf + 4);
317 }
318
319 static void
mips_store_fpregset(struct regcache * regcache,const void * buf)320 mips_store_fpregset (struct regcache *regcache, const void *buf)
321 {
322 const union mips_register *regset = buf;
323 int i, use_64bit, first_fp, big_endian;
324
325 use_64bit = (register_size (0) == 8);
326 first_fp = find_regno ("f0");
327 big_endian = (__BYTE_ORDER == __BIG_ENDIAN);
328
329 /* See GDB for a discussion of this peculiar layout. */
330 for (i = 0; i < 32; i++)
331 if (use_64bit)
332 supply_register (regcache, first_fp + i, regset[i].buf);
333 else
334 supply_register (regcache, first_fp + i,
335 regset[i & ~1].buf + 4 * (big_endian != (i & 1)));
336
337 mips_supply_register_32bit (regcache, use_64bit,
338 find_regno ("fcsr"), regset[32].buf);
339 mips_supply_register_32bit (regcache, use_64bit, find_regno ("fir"),
340 regset[32].buf + 4);
341 }
342 #endif /* HAVE_PTRACE_GETREGS */
343
344 struct regset_info target_regsets[] = {
345 #ifdef HAVE_PTRACE_GETREGS
346 { PTRACE_GETREGS, PTRACE_SETREGS, 0, 38 * 8, GENERAL_REGS,
347 mips_fill_gregset, mips_store_gregset },
348 { PTRACE_GETFPREGS, PTRACE_SETFPREGS, 0, 33 * 8, FP_REGS,
349 mips_fill_fpregset, mips_store_fpregset },
350 #endif /* HAVE_PTRACE_GETREGS */
351 { 0, 0, 0, -1, -1, NULL, NULL }
352 };
353
354 struct linux_target_ops the_low_target = {
355 #ifdef __mips64
356 init_registers_mips64_linux,
357 #else
358 init_registers_mips_linux,
359 #endif
360 mips_num_regs,
361 mips_regmap,
362 mips_cannot_fetch_register,
363 mips_cannot_store_register,
364 mips_get_pc,
365 mips_set_pc,
366 (const unsigned char *) &mips_breakpoint,
367 mips_breakpoint_len,
368 mips_reinsert_addr,
369 0,
370 mips_breakpoint_at,
371 };
372